1
|
Smith TJ. TSHR-IGF-IR complex drives orbital fibroblast misbehavior in thyroid eye disease. Curr Opin Endocrinol Diabetes Obes 2024; 31:177-183. [PMID: 39082947 DOI: 10.1097/med.0000000000000878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 09/03/2024]
Abstract
PURPOSE OF REVIEW Evolving understanding of thyroid eye disease (TED) has led to rapidly advancing therapeutic options. Most new treatments under development or recently available to patients are predicated on insights into disease mechanism. RECENT FINDINGS TED, a disfiguring process, involves inflammation and remodeling of the connective tissues around the eye. TED most frequently presents as a component of Graves' disease. Advances in our understanding of cells involved in TED and their molecular interactions have led to novel therapeutic targets. Among these cell types are orbital fibroblasts and a subset comprising monocyte progenitor cells, known as CD34 + CXCR4 + fibrocytes. Among the attributes of fibrocytes is their expression of several autoantigens associated with Graves' disease, including TSHR, thyroglobulin and thyroperoxidase. Fibrocytes also express high levels of the insulin-like growth factor-I (IGF-I) receptor, thought to mediate fibroblast activation. Therapeutically targeting the TSHR/IGF-IR receptor complex using an IGF-I receptor antagonist, teprotumumab, has resulted in substantial clinical benefit for patients with TED. The neural axon repellent, Slit2, and its cognate receptor, ROBO1, appear to modulate the inflammatory phenotype of these orbit-infiltrating fibrocytes. SUMMARY More detailed understanding of orbital fibroblasts and the distinctions between cell subsets comprising them should lead to more effective therapies with fewer side effects.
Collapse
Affiliation(s)
- Terry J Smith
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
| |
Collapse
|
2
|
Qi X, Luo B, Deng M, Cao J, Hou S, Xie Z, Tong B, Xiong W. Botox-A improve the thyroid-associated ophthalmopathy (TAO) orbital fibroblast activation through inhibiting the TGF-β/Smad signaling. Exp Eye Res 2022; 217:108971. [PMID: 35108585 DOI: 10.1016/j.exer.2022.108971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 11/08/2021] [Accepted: 01/26/2022] [Indexed: 11/04/2022]
Abstract
The activation of orbital fibroblasts can result in fibrosis, finally contributing to thyroid-associated ophthalmopathy (TAO) progression. Although the effect of BTX-A on the treatment of TAO-related strabismus and upper eyelid retraction has long been recognized in clinical work, the underlying mechanism of BTX-A improving TAO-related strabismus and upper eyelid retraction has not been uncovered yet. In the present study, we successfully isolated and authenticated normal and TAO orbital fibroblasts. Compared with PBS, BTX-A and TACA exerted similar inhibitory effects on TAO orbital fibroblast proliferation and ECM production. TGF-β stimulation induced the proliferation and ECM production by TAO orbital fibroblast, which was significantly inhibited by BTX-A or TACA treatment. Under TGF-β stimulation, the inhibitory effects of BTX-A or TACA treatment on TAO orbital fibroblast proliferation and ECM production were reversed by TGF-β/Smad signaling agonist SRI-011381. Collectively, BTX-A inhibited TGF-β-induced TAO orbital fibroblast activation through inhibiting the TGF-β/Smad signaling. Considering that TACA shows no satisfactory curative effects on symptoms closely related to the function of extraocular muscles, such as eye movement and diplopia, BTX-A might be a promising agent in TAO treatment.
Collapse
Affiliation(s)
- Xin Qi
- Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China
| | - Ban Luo
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, China
| | - Mi Deng
- Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China
| | - Jiamin Cao
- Department of Ophthalmology, The Third Xiangya Hospital, Central South University, Changsha, Hunan, 410013, China
| | - Shiying Hou
- Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China
| | - Zhaoyu Xie
- Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China
| | - Boding Tong
- Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China.
| | - Wei Xiong
- Department of Ophthalmology, The Third Xiangya Hospital, Central South University, Changsha, Hunan, 410013, China.
| |
Collapse
|
3
|
Smith TJ. Teprotumumab as a Novel Therapy for Thyroid-Associated Ophthalmopathy. Front Endocrinol (Lausanne) 2020; 11:610337. [PMID: 33391187 PMCID: PMC7774640 DOI: 10.3389/fendo.2020.610337] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 11/10/2020] [Indexed: 12/24/2022] Open
Abstract
Thyroid-associated ophthalmopathy (TAO) has remained a vexing and poorly managed autoimmune component of Graves' disease where the tissues surrounding the eye and in the upper face become inflamed and undergo remodeling. This leads to substantial facial disfigurement while in its most severe forms, TAO can threaten eye sight. In this brief paper, I review some of the background investigation that has led to development of teprotumumab as the first and only US FDA approved medical therapy for TAO. This novel treatment was predicated on recognition that the insulin-like growth factor I receptor plays an important role in the pathogenesis of TAO. It is possible that a similar involvement of that receptor in other autoimmune disease may lead to additional indications for this and alternative insulin-like growth factor I receptor-inhibiting strategies.
Collapse
Affiliation(s)
- Terry J. Smith
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, Ann Arbor, MI, United States
- Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, United States
- *Correspondence: Terry J. Smith,
| |
Collapse
|
4
|
Graves' disease: Introduction, epidemiology, endogenous and environmental pathogenic factors. ANNALES D'ENDOCRINOLOGIE 2018; 79:599-607. [PMID: 30342794 DOI: 10.1016/j.ando.2018.09.002] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Graves' disease is the most frequent cause of hyperthyroidism. Many questions remain about the choice of diagnostic evaluations and treatment strategy according to clinical context (age, gender, pregnancy, etc.) and about the best management of the main extrathyroidal complication that is Graves orbitopathy. The exact pathogenic mechanisms are not fully clear. They associate genetic factors, interactions between endogenous and environmental factors, and immune system dysregulation. Graves' orbitopathy is one of the consequences of this partial understanding. Iatrogenic Graves' disease induced by the new targeted therapies are described and could help to better understand the molecular pathways involved in the disease and to develop new therapeutic approaches.
Collapse
|
5
|
Association between CD40 rs1883832 and immune-related diseases susceptibility: A meta-analysis. Oncotarget 2017; 8:102235-102243. [PMID: 29254239 PMCID: PMC5731949 DOI: 10.18632/oncotarget.18704] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 06/17/2017] [Indexed: 12/31/2022] Open
Abstract
Background/objective It has been reported that CD40 rs1883832 might be associated with immune-related diseases susceptibility. Owing to mixed and inconclusive results, we conducted a meta-analysis of case–control studies to summarize and clarify this association. Methods/main results A systematic search of studies on the association between CD40 rs1883832 and immune-related diseases susceptibility was conducted in databases. Odds ratios and 95% confidence intervals were used to pool the effect size. 40 articles were included in our meta-analysis. Conclusions CD40 rs1883832 is associated with decreased risk of Graves’ disease, especially in Asian; CD40 rs1883832 is associated with increased risk of multiple sclerosis; CD40 -1C>T (rs1883832) is not associated with the susceptibility of Hashimoto's thyroiditis, systemic sclerosis or Asthma; there is insufficient data to fully confirm the association between CD40 rs1883832 and systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), Behçet's disease (BD), myasthenia gravis (MG), Crohn's disease (CD), ulcerative colitis (UC), Sarcoidosis, Fuch uveitis syndrome (FUS), Vogt-Koyanagi-Harada syndrome (VKH), Kawasaki disease (KD), giant cell arteritis (GCA) or Immune thrombocytopenia (ITP).
Collapse
|
6
|
Gillespie EF, Raychaudhuri N, Papageorgiou KI, Atkins SJ, Lu Y, Charara LK, Mester T, Smith TJ, Douglas RS. Interleukin-6 production in CD40-engaged fibrocytes in thyroid-associated ophthalmopathy: involvement of Akt and NF-κB. Invest Ophthalmol Vis Sci 2012; 53:7746-53. [PMID: 23092922 DOI: 10.1167/iovs.12-9861] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
PURPOSE CD40-CD40 ligand (CD40L) interactions appear to play pathogenic roles in autoimmune disease. Here we quantify CD40 expression on fibrocytes, circulating, and bone marrow-derived progenitor cells. The functional consequences of CD40 ligation are determined since these may promote tissue remodeling linked with thyroid-associated ophthalmopathy (TAO). METHODS CD40 levels on cultivated fibrocytes and orbital fibroblasts (GOFB) from patients with Graves' disease (GD), as well as fibrocyte abundance, were determined by flow cytometry. CD40 mRNA expression was evaluated by real-time PCR, whereas response to CD40 ligation was measured by Luminex and RT-PCR. Protein kinase B (Akt) and nuclear factor (NF)-kappa B (NF-κB) signaling were determined by Western blot and immunofluorescence. RESULTS Basal CD40 expression on fibrocytes is greater than that on GOFB. IFN-γ upregulates CD40 in both cell types and its actions are mediated at the pretranslational level. Fibrocytes produce high levels of cytokines, including interleukin-6 (IL-6), TNF-α, IL-8, MCP-1, and RANTES (Regulated on Activation, Normal T Cell Expressed and Secreted) in response to CD40L. IL-6 induction results from an increase in steady state IL-6 mRNA, and is mediated through Akt and NF-κB activation. Circulating CD40(+)CD45(+)Col1(+) fibrocytes are far more frequent in vivo in donors with TAO compared with healthy subjects. CONCLUSIONS Particularly high levels of functional CD40 are displayed by fibrocytes. CD40L-provoked signaling results in the production of several cytokines. Among these, IL-6 expression is mediated through Akt and NF-κB pathways. The frequency of circulating CD40(+) fibrocytes is markedly increased in patients with TAO, suggesting that this receptor might represent a therapeutic target for TAO.
Collapse
Affiliation(s)
- Erin F Gillespie
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Kellogg Eye Center, Ann Arbor, Michigan 48105, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Płoski R, Szymański K, Bednarczuk T. The genetic basis of graves' disease. Curr Genomics 2012; 12:542-63. [PMID: 22654555 PMCID: PMC3271308 DOI: 10.2174/138920211798120772] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 08/05/2011] [Accepted: 08/15/2011] [Indexed: 01/09/2023] Open
Abstract
The presented comprehensive review of current knowledge about genetic factors predisposing to Graves’ disease (GD) put emphasis on functional significance of observed associations. In particular, we discuss recent efforts aimed at refining diseases associations found within the HLA complex and implicating HLA class I as well as HLA-DPB1 loci. We summarize data regarding non-HLA genes such as PTPN22, CTLA4, CD40, TSHR and TG which have been extensively studied in respect to their role in GD. We review recent findings implicating variants of FCRL3 (gene for FC receptor-like-3 protein), SCGB3A2 (gene for secretory uteroglobin-related protein 1- UGRP1) as well as other unverified possible candidate genes for GD selected through their documented association with type 1 diabetes mellitus: Tenr–IL2–IL21, CAPSL (encoding calcyphosine-like protein), IFIH1(gene for interferon-induced helicase C domain 1), AFF3, CD226 and PTPN2. We also review reports on association of skewed X chromosome inactivation and fetal microchimerism with GD. Finally we discuss issues of genotype-phenotype correlations in GD.
Collapse
Affiliation(s)
- Rafał Płoski
- Department of Medical Genetics, Centre for Biostructure, Medical University of Warsaw, Poland
| | | | | |
Collapse
|
8
|
Li M, Sun H, Liu S, Yu J, Li Q, Liu P, Shen H, Sun D. CD40 C/T-1 polymorphism plays different roles in Graves' disease and Hashimoto's thyroiditis: a meta-analysis. Endocr J 2012; 59:1041-50. [PMID: 22863718 DOI: 10.1507/endocrj.ej12-0126] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
CD40 plays a pathogenic role in various autoimmune diseases. However, studies investigating the association between CD40 C/T-1 polymorphism and autoimmune thyroid diseases risk have reported conflicting results and their relative population effect remains unclear; therefore, a meta-analysis was conducted. The data for this meta-analysis included 14 (4214 cases and 3851 controls) and 4 studies (623 cases and 774 controls) for the association of the CD40 C/T-1 polymorphism with Graves' disease (GD) and Hashimoto's thyroiditis (HT), respectively. Results suggested significant association for CD40 C/T-1 polymorphism (odds ratio 1.267 per C allele, p = 0.000) with GD but without HT. The individuals who carried the C/C or C/T genotype have significantly increased GD risk compared with those who carried T/T genotype (C/C vs. T/T: OR = 1.596, 95% CI, 1.256~2.028; C/T vs. T/T: OR = 1.210, 95% CI, 1.032~1.419; dominant model: OR = 1.366, 95% CI, 1.175~1.587; recessive model: OR = 1.322, 95% CI, 1.147~1.523), while no association was observed in HT. When stratified by ethnicity, the significant association between polymorphism and GD risk of Caucasians was found only in recessive models; but that of Asians was found in all models. In the subgroup analysis of study design, we found thyroid antibody status should be ascertained in controls and euthyroidism subjects with higher levels of thyroid antibody should be excluded from control and included into HT to avoid bias. Our meta-analysis showed that CD40 C/T-1 polymorphism plays different roles in GD and HT. Further studies will be needed to confirm our findings.
Collapse
Affiliation(s)
- Ming Li
- Institute of Iodine Deficiency Disorders, Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, China
| | | | | | | | | | | | | | | |
Collapse
|
9
|
Smith TJ, Padovani-Claudio DA, Lu Y, Raychaudhuri N, Fernando R, Atkins S, Gillespie EF, Gianoukakis AG, Miller BS, Gauger PG, Doherty GM, Douglas RS. Fibroblasts expressing the thyrotropin receptor overarch thyroid and orbit in Graves' disease. J Clin Endocrinol Metab 2011; 96:3827-37. [PMID: 21956421 PMCID: PMC3232631 DOI: 10.1210/jc.2011-1249] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
CONTEXT Graves' disease (GD) is a systemic autoimmune syndrome comprising manifestations in thyroid and orbital connective tissue. The link between these two tissues in GD eludes our understanding. Patients with GD have increased frequency of circulating monocyte lineage cells known as fibrocytes. These fibrocytes infiltrate orbital connective tissues in thyroid-associated ophthalmopathy and express functional TSH receptor (TSHR). OBJECTIVE The aim of the study was to identify and characterize CD34(+) fibrocytes in thyroid tissue. DESIGN/SETTING/PARTICIPANTS Patients undergoing surgical thyroidectomy at two academic medical centers were recruited to the study. MAIN OUTCOME MEASURES We performed immunohistochemistry, flow cytometry, real-time PCR, cytokine-specific ELISA, and cell differentiation. RESULTS CD34(+)ColI(+)CXCR4(+)TSHR(+) cells can be identified in situ in thyroid tissue from donors with GD, Hashimoto's thyroiditis, or in normal-appearing tissue. Thyroid fibroblasts cultivated from these glands express a CD34(-)ColI(+)CXCR4(+)TSHR(+) phenotype. TSHR levels are higher than those in orbital fibroblasts. When treated with TSH, thyroid fibroblasts generate IL-6 and IL-8. The induction of IL-6 can be blocked by dexamethasone, a chemical inhibitor of Akt/Pkb, and by knocking down Akt with a specific small interfering RNA. When treated with TGF-β or rosiglitazone, thyroid fibroblasts differentiate into myofibrocytes or adipocytes, respectively. CONCLUSIONS ColI(+)CXCR4(+)TSHR(+) thyroid fibroblasts resemble orbital fibroblasts and circulating fibrocytes. CD34(+) fibrocytes appear to infiltrate both tissues in GD. Thyroid fibroblasts lose CD34 display in culture, unlike orbital fibroblasts and circulating fibrocytes. Fibrocytes and their fibroblast derivatives may participate in the pathogenesis of thyroid autoimmunity after TSHR activation. They could represent a therapeutic target for these diseases.
Collapse
Affiliation(s)
- Terry J Smith
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Kellogg Eye Center, Brehm Tower, 1000 Wall Street, Ann Arbor, Michigan 48105, USA.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Regulation of Lymphocyte Function by PPARgamma: Relevance to Thyroid Eye Disease-Related Inflammation. PPAR Res 2011; 2008:895901. [PMID: 18354731 PMCID: PMC2266979 DOI: 10.1155/2008/895901] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2007] [Accepted: 12/12/2007] [Indexed: 01/28/2023] Open
Abstract
Thyroid eye disease (TED) is an autoimmune condition in which intense inflammation leads to orbital tissue remodeling, including the accumulation of extracellular macromolecules and fat. Disease progression depends upon interactions between lymphocytes and orbital fibroblasts. These cells engage in a cycle of reciprocal activation which produces the tissue characteristics of TED. Peroxisome proliferator-activated receptor-gamma (PPARgamma) may play divergent roles in this process, both attenuating and promoting disease progression. PPARgamma has anti-inflammatory activity, suggesting that it could interrupt intercellular communication. However, PPARgamma activation is also critical to adipogenesis, making it a potential culprit in the pathological fat accumulation associated with TED. This review explores the role of PPARgamma in TED, as it pertains to crosstalk between lymphocytes and fibroblasts and the development of therapeutics targeting cell-cell interactions mediated through this signaling pathway.
Collapse
|
11
|
Shan B, Hagood JS, Zhuo Y, Nguyen HT, MacEwen M, Morris GF, Lasky JA. Thy-1 attenuates TNF-alpha-activated gene expression in mouse embryonic fibroblasts via Src family kinase. PLoS One 2010; 5:e11662. [PMID: 20657842 PMCID: PMC2906514 DOI: 10.1371/journal.pone.0011662] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2009] [Accepted: 06/22/2010] [Indexed: 11/18/2022] Open
Abstract
Heterogeneous surface expression of Thy-1 in fibroblasts modulates inflammation and may thereby modulate injury and repair. As a paradigm, patients with idiopathic pulmonary fibrosis, a disease with pathologic features of chronic inflammation, demonstrate an absence of Thy-1 immunoreactivity within areas of fibrotic activity (fibroblast foci) in contrast to the predominant Thy-1 expressing fibroblasts in the normal lung. Likewise, Thy-1 deficient mice display more severe lung fibrosis in response to an inflammatory injury than wildtype littermates. We investigated the role of Thy-1 in the response of fibroblasts to the pro-inflammatory cytokine TNF-alpha. Our study demonstrates distinct profiles of TNF-alpha-activated gene expression in Thy-1 positive (Thy-1+) and negative (Thy-1-) subsets of mouse embryonic fibroblasts (MEF). TNF-alpha induced a robust activation of MMP-9, ICAM-1, and the IL-8 promoter driven reporter in Thy-1- MEFs, in contrast to only a modest increase in Thy-1+ counterparts. Consistently, ectopic expression of Thy-1 in Thy-1- MEFs significantly attenuated TNF-alpha-activated gene expression. Mechanistically, TNF-alpha activated Src family kinase (SFK) only in Thy-1- MEFs. Blockade of SFK activation abrogated TNF-alpha-activated gene expression in Thy-1- MEFs, whereas restoration of SFK activation rescued the TNF-alpha response in Thy-1+ MEFs. Our findings suggest that Thy-1 down-regulates TNF-alpha-activated gene expression via interfering with SFK- and NF-kappaB-mediated transactivation. The current study provides a novel mechanistic insight to the distinct roles of fibroblast Thy-1 subsets in inflammation.
Collapse
Affiliation(s)
- Bin Shan
- Department of Medicine, Tulane University Health Sciences Center, New Orleans, Louisiana, United States of America
| | - James S. Hagood
- Department of Pediatrics, University of Alabama-Birmingham School of Medicine, Birmingham, Alabama, United States of America
| | - Ying Zhuo
- Department of Medicine, Tulane University Health Sciences Center, New Orleans, Louisiana, United States of America
| | - Hong T. Nguyen
- Department of Medicine, Tulane University Health Sciences Center, New Orleans, Louisiana, United States of America
| | - Mark MacEwen
- Department of Pediatrics, University of Alabama-Birmingham School of Medicine, Birmingham, Alabama, United States of America
| | - Gilbert F. Morris
- Department of Pathology, Tulane University Health Sciences Center, New Orleans, Louisiana, United States of America
| | - Joseph A. Lasky
- Department of Medicine, Tulane University Health Sciences Center, New Orleans, Louisiana, United States of America
- * E-mail: .
| |
Collapse
|
12
|
Douglas RS, Afifiyan NF, Hwang CJ, Chong K, Haider U, Richards P, Gianoukakis AG, Smith TJ. Increased generation of fibrocytes in thyroid-associated ophthalmopathy. J Clin Endocrinol Metab 2010; 95:430-8. [PMID: 19897675 PMCID: PMC2805489 DOI: 10.1210/jc.2009-1614] [Citation(s) in RCA: 131] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
CONTEXT The pathogenic basis for Graves' disease (GD) continues to elude our understanding. Specifically why activating antibodies are generated against self-antigens remains uncertain as does the identity of the antigen(s) that provokes orbital involvement in GD, a process known as thyroid-associated ophthalmopathy (TAO). OBJECTIVE The aim of the study was to determine whether CD34(+) fibrocytes are generated more frequently in GD, whether they infiltrate orbital connective tissues in TAO, and whether they express the thyrotropin receptor (TSHR). DESIGN/SETTING/PARTICIPANTS Generation of fibrocytes from peripheral blood mononuclear cells was examined in samples from 70 patients with GD and 25 healthy control subjects. Fibrocytes were characterized by flow cytometry. Orbital tissues and fibroblast culture strains were examined for their presence. MAIN OUTCOME MEASURES The frequency of CD34(+) fibrocyte generation from peripheral blood cells, characterization of their phenotype, cytokine production, and their presence in affected orbital tissues were analyzed. RESULTS CD34(+)CXCR4(+)Col I(+) fibrocytes expressing IGF-I receptor are far more frequently generated from cultured peripheral blood mononuclear cells of donors with GD compared with healthy subjects. They express TSHR at high levels and TSH induces fibrocytes to produce IL-6 and TNF-alpha. Numerous CD34(+) fibrocytes were detected in orbital tissues in TAO but were absent in healthy orbits. Tissue-infiltrating fibrocytes express TSHR in situ and comprise a subpopulation of TAO-derived orbital fibroblasts. CONCLUSIONS Our findings suggest that fibrocytes may participate in the pathogenesis of TAO because they express relevant autoantigens such as IGF-I receptor and functional TSHR and differentially accumulate in orbital tissue in TAO.
Collapse
Affiliation(s)
- Raymond S Douglas
- Divisions of Molecular Medicine, Department of Medicine, Harbor-University of California, Los Angeles, Medical Center, Torrance, California 90502, USA
| | | | | | | | | | | | | | | |
Collapse
|
13
|
Abstract
Migration of dendritic cells (DCs) from skin to lymph nodes on activation is an essential step in the initiation of an adequate immune response. The dermal microenvironment including stromal cells and their soluble factors might be involved in the regulation of DC migration. To focus on the role of dermal fibroblasts, we studied whether interaction of DCs with fibroblasts promotes the migration of DCs. DCs were co-cultured with resting fibroblasts or with tumor necrosis factor (TNF)alpha/IL-1beta-activated fibroblasts to mimic an inflammatory microenvironment. Interaction of DCs with TNFalpha/IL-1beta-stimulated fibroblasts increased the secretion of matrix metalloproteinase-9 (MMP-9) from DCs within 6 hours compared with DCs alone or DCs stimulated with lipopolysaccharide or TNFalpha/IL-1beta. In contrast, unstimulated fibroblasts did not affect MMP-9 secretion. IL-6 released by TNFalpha/IL-1beta-stimulated fibroblasts was identified as a factor responsible for fibroblast-stimulated MMP-9 secretion from DCs. In accordance with the elevated MMP-9 release, on co-culture with TNFalpha/IL-1beta-stimulated fibroblasts, DCs migrated significantly more effectively through matrigel matrices than did TNFalpha/IL-1beta-stimulated DCs. This was inhibited by a selective blocking of MMP-9, indicating the importance of MMP-9 for this migratory capacity of DCs. In summary, fibroblasts in the local dermal microenvironment are capable of potentiating the migratory capacity of DCs, and thus have the potential to actively participate in the regulation of a cutaneous immune response.
Collapse
|
14
|
Douglas RS, Gianoukakis AG, Goldberg RA, Kamat S, Smith TJ. Circulating mononuclear cells from euthyroid patients with thyroid-associated ophthalmopathy exhibit characteristic phenotypes. Clin Exp Immunol 2007; 148:64-71. [PMID: 17349012 PMCID: PMC1868859 DOI: 10.1111/j.1365-2249.2006.03316.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Thyroid-associated ophthalmopathy (TAO) is a common yet poorly understood component of Graves' disease involving inflammation, congestion and soft tissue remodelling of the orbit. Unlike most autoimmune disorders, TAO has variable severity but follows a predictable course and is usually self-limited. The objective of this study was to investigate the phenotypic profile of peripheral blood mononuclear cells in euthyroid patients with TAO. The study was a prospective, consecutive analysis of the peripheral blood mononuclear cell phenotype in patients with TAO and normal controls. We demonstrate that the fraction of T cells expressing CD69, CD25 or CXCR4 is significantly greater in patients with TAO compared to control donors. In addition, the fraction of CD19(+) CD25(+) B cells is significantly greater. We did not find differences between the two groups of subjects in monocytes expressing these markers. There is a phenotypic shift in peripheral blood lymphocytes associated with TAO that appears durable and persists beyond the hyperthyroid phase of Graves' disease. These changes may support the immune reaction provoking orbital disease development.
Collapse
Affiliation(s)
- R S Douglas
- Division of Molecular Medicine, Department of Medicine, Harbor-UCLA Medical Center, Torrance, CA 90502, USA
| | | | | | | | | |
Collapse
|
15
|
Drexhage HA. Are there more than antibodies to the thyroid-stimulating hormone receptor that meet the eye in Graves' disease? Endocrinology 2006; 147:9-12. [PMID: 16365140 DOI: 10.1210/en.2005-1305] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- H A Drexhage
- Department of Immunology, Erasmus MC, P.O. Box 1738, 3000 DR Rotterdam, The Netherlands.
| |
Collapse
|
16
|
Jacobson EM, Concepcion E, Oashi T, Tomer Y. A Graves' disease-associated Kozak sequence single-nucleotide polymorphism enhances the efficiency of CD40 gene translation: a case for translational pathophysiology. Endocrinology 2005; 146:2684-91. [PMID: 15731360 DOI: 10.1210/en.2004-1617] [Citation(s) in RCA: 162] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We analyzed the mechanism by which a Graves' disease-associated C/T polymorphism in the Kozak sequence of CD40 affects CD40 expression. CD40 expression levels on B cells in individuals with CT and TT genotypes were decreased by 13.3 and 39.4%, respectively, compared with the levels in CC genotypes (P = 0.012). Similarly, Rat-2 fibroblasts transfected with T-allele cDNA expressed 32.2% less CD40 compared with their C-allele-transfected counterparts (P = 0.004). Additionally, an in vitro transcription/translation system showed that the T-allele makes 15.5% less CD40 than the C-allele (P < 0.001), demonstrating that the effect of the single-nucleotide polymorphism (SNP) on CD40 expression is at the level of translation. However, the SNP did not affect transcription, because the mRNA levels of CD40, as measured by quantitative RT-PCR, were independent of genotype. Therefore, our results may suggest that the C allele of the CD40 Kozak SNP, which is associated with Graves' disease, could predispose to disease by increasing the efficiency of translation of CD40 mRNA.
Collapse
Affiliation(s)
- Eric M Jacobson
- Division of Endocrinology, Box 1055, Mount Sinai School of Medicine, One Gustave L. Levy Place, New York, New York 10029, USA.
| | | | | | | |
Collapse
|
17
|
Eckstein AK, Quadbeck B, Tews S, Mann K, Krüger C, Mohr CH, Steuhl KP, Esser J, Gieseler RK. Thyroid associated ophthalmopathy: evidence for CD4(+) gammadelta T cells; de novo differentiation of RFD7(+) macrophages, but not of RFD1(+) dendritic cells; and loss of gammadelta and alphabeta T cell receptor expression. Br J Ophthalmol 2004; 88:803-8. [PMID: 15148216 PMCID: PMC1772193 DOI: 10.1136/bjo.2003.035915] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
AIM To characterise periorbital immune cells (stages, kinetics) in active and inactive thyroid associated ophthalmopathy (A-TAO; I-TAO). METHODS In orbital tissue cryosections of patients with A-TAO (n = 15), I-TAO (n = 11), and healthy controls (n = 14), adipose and fibrovascular areas were evaluated for MHC II(+) cells, CD45(+) total leukocytes, myeloid cells (CD33(+) monocytes; CD14(+) macrophages; mature RFD7(+) macrophages; RFD1(+) dendritic cells (DCs)), and lymphoid cells (CD4(+) T cells; alphabeta and gammadelta T cells; CD20(+) B cells). Results are expressed as medians and 5% confidence intervals. RESULTS In fibrovascular septae, a surge of CD33(+) immigrants clearly correlating with disease activity generated significantly increased (p<0.05) percentages of CD14(+) and RFD7(+) macrophages. Intriguingly, CD4(+) cells were mostly gammadelta T cells, while alphabeta T helper cells were much less frequent. Successful treatment rendering TAO inactive apparently downregulates monocyte influx, macrophage differentiation, and T cell receptor expression. Similar trends were recorded for adipose tissue. Interestingly, RFD1(+) DCs were completely absent from all conditions examined. CONCLUSION A-TAO coincides with periorbital monocyte infiltration and de novo differentiation of macrophages, but not DCs. The authors discuss a novel potential role for inflammatory CD4(+) gammadelta T cells in TAO. Successful treatment apparently downregulates orbital monocyte recruitment and effects functional T cell knockout.
Collapse
Affiliation(s)
- A K Eckstein
- Department of Ophthalmology, Essen University Hospital, Essen, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Luft T, Jefford M, Luetjens P, Toy T, Hochrein H, Masterman KA, Maliszewski C, Shortman K, Cebon J, Maraskovsky E. Functionally distinct dendritic cell (DC) populations induced by physiologic stimuli: prostaglandin E(2) regulates the migratory capacity of specific DC subsets. Blood 2002; 100:1362-72. [PMID: 12149219 DOI: 10.1182/blood-2001-12-0360] [Citation(s) in RCA: 286] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Migration of antigen (Ag)-loaded dendritic cells (DCs) from sites of infection into draining lymphoid tissues is fundamental to the priming of T-cell immune responses. We evaluated monocyte-derived DCs (MoDCs) and peripheral blood DCs (PBDCs) to respond to proinflammatory mediators, CD40L, and intact bacteria. All classes of stimuli induced DC phenotypic maturation. However, for MoDCs, only prostaglandin E(2) (PGE(2))-containing stimuli induced migratory-type DCs. Thus, immature MoDCs that encountered proinflammatory cytokines or CD40L or intact bacteria in the presence of PGE(2) acquired migratory capacity but secreted low levels of cytokines. Conversely, MoDCs that encountered pathogens or CD40L alone become nonmigratory cytokine-secreting cells (proinflammatory type). Interestingly, both migratory- and proinflammatory-type DCs expressed equivalent levels of chemokine receptors, suggesting that the role of PGE(2) was to switch on migratory function. We demonstrate that PGE(2) induces migration via the E-prostanoid 2/E-prostanoid 4 (EP(2)/EP(4)) receptors and the cAMP pathway. Finally, migratory-type MoDCs stimulated T-cell proliferation and predominantly IL-2 secretion, whereas proinflammatory-type MoDCs induced IFN-gamma production. In contrast, CD1b/c(+) PBDC rapidly acquired migratory capacity irrespective of the class of stimulus encountered and secreted low levels of cytokines. This suggests that not all mature stages of DCs are destined to migrate to lymphoid organs and that the sequence in which stimuli are encountered significantly affects which functions are expressed. Thus, certain immature DC subsets recruited from the resting precursor pool may have multiple functional fates that play distinct roles during the induction and effector phases of the immune response. These findings have important implications for the clinical utility of DCs in immunotherapy.
Collapse
MESH Headings
- CD40 Ligand/physiology
- Cell Differentiation
- Cell Movement/drug effects
- Cells, Cultured
- Chemotaxis
- Cyclic AMP/metabolism
- Cytokines/metabolism
- Dendritic Cells/drug effects
- Dendritic Cells/physiology
- Dinoprostone/pharmacology
- Dinoprostone/physiology
- Escherichia coli
- Humans
- Interferon-gamma/biosynthesis
- Interleukin-2/metabolism
- Leukocytes, Mononuclear/drug effects
- Leukocytes, Mononuclear/physiology
- Lymphocyte Activation
- Monocytes/drug effects
- Monocytes/physiology
- Phenotype
- Receptors, CCR7
- Receptors, CXCR4/analysis
- Receptors, Chemokine/analysis
- Receptors, Prostaglandin E/physiology
- Receptors, Prostaglandin E, EP2 Subtype
- Receptors, Prostaglandin E, EP4 Subtype
- Signal Transduction
- T-Lymphocytes/immunology
Collapse
Affiliation(s)
- Thomas Luft
- The Melbourne Tumour Biology Branch, The Ludwig Institute for Cancer Research, Austin and Repatriation Medical Centre, Heidelberg, Victoria, Australia
| | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Koumas L, King AE, Critchley HO, Kelly RW, Phipps RP. Fibroblast heterogeneity: existence of functionally distinct Thy 1(+) and Thy 1(-) human female reproductive tract fibroblasts. THE AMERICAN JOURNAL OF PATHOLOGY 2001; 159:925-35. [PMID: 11549585 PMCID: PMC1850439 DOI: 10.1016/s0002-9440(10)61768-3] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Little is known about fibroblasts from the female reproductive tract, much less whether or not functional subsets exist. Fibroblasts are key as sentinel cells for recruiting white blood cells and for wound healing. The purpose of this research was to evaluate the possibility that functional subsets of fibroblasts exist in the human female reproductive tract. The strategy used was to define fibroblast subpopulations based on their surface expression of the Thy 1 antigen. In situ staining of human myometrium and endometrium showed heterogeneous staining for Thy 1. Freshly derived strains of fibroblasts from the myometrium and endometrium also demonstrated heterogeneous Thy 1 expression. For the first time, using magnetic beading and fluorescence-activated cell sorting, human myometrial fibroblasts were successfully separated into functionally unique Thy 1(+) and Thy 1(-) subsets. Both subsets produced the proinflammatory cytokines interleukin (IL)-6 and IL-8 after IL-1beta stimulation, but only the Thy 1(+) subset produced MCP-1. Furthermore, only Thy 1(+) fibroblasts up-regulated CD40 surface expression with IL-1beta or interferon-gamma treatment. Engagement of CD40 in the Thy 1(+) subpopulation induced IL-6, IL-8, and MCP-1. The discovery of functional subsets of reproductive tract fibroblasts now permits assessment of their roles in the normal functions of the reproductive tract and in disease states such as adhesions and menorrhagia.
Collapse
Affiliation(s)
- L Koumas
- Department of Microbiology and Immunology, Cancer Center, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, USA
| | | | | | | | | |
Collapse
|
20
|
Cao HJ, Smith TJ. Leukoregulin upregulation of prostaglandin endoperoxide H synthase-2 expression in human orbital fibroblasts. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 277:C1075-85. [PMID: 10600759 DOI: 10.1152/ajpcell.1999.277.6.c1075] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Human orbital fibroblasts from patients with severe thyroid-associated ophthalmopathy are particularly susceptible to the actions of a variety of proinflammatory molecules. In this study, we demonstrate that the inductions of prostaglandin endoperoxide H synthase-2 (PGHS-2), interleukin (IL)-1alpha, and IL-1beta by leukoregulin, a product of activated T lymphocytes, are far more robust in orbital fibroblasts than those observed in dermal fibroblasts. These actions of leukoregulin are mediated through an intermediate induction of IL-1alpha. In contrast, leukoregulin also induces IL-1-receptor antagonist (IL-1ra) expression in orbital fibroblasts, but this induction is considerably greater in dermal fibroblasts (2.3- vs. 8.5-fold). Interrupting the effects of IL-1alpha, either with a neutralizing antibody or with exogenous IL-1ra, can block the induction of PGHS-2 by leukoregulin. Leukoregulin increases PGHS-2 gene transcription in orbital fibroblasts but exerts the major effect on cyclooxygenase expression by enhancing the stability of mature PGHS-2 mRNA. The cytokine triggers nuclear translocation of nuclear factor-kappaB (NF-kappaB) p50/p50 homodimers and p50/p65 heterodimers, and an inhibitor of this transcriptional factor, pyrrolidinedithiocarbamate, can attenuate the PGHS-2 induction. Thus differential inducibility of the members of the IL-1 family of genes in orbital fibroblasts would appear to underlie, at least in part, the differences in PGHS-2 induction observed in orbital and dermal fibroblasts. NF-kappaB plays an important role in mediating the effects of leukoregulin on PGHS-2 expression.
Collapse
Affiliation(s)
- H J Cao
- Division of Molecular and Cellular Medicine, Departments of Medicine and Biochemistry and Molecular Biology, Albany Medical College and Samuel S. Stratton Veterans Affairs Medical Center, Albany, New York 12208, USA
| | | |
Collapse
|
21
|
Kaback LA, Smith TJ. Expression of hyaluronan synthase messenger ribonucleic acids and their induction by interleukin-1beta in human orbital fibroblasts: potential insight into the molecular pathogenesis of thyroid-associated ophthalmopathy. J Clin Endocrinol Metab 1999; 84:4079-84. [PMID: 10566653 DOI: 10.1210/jcem.84.11.6111] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The disordered accumulation of hyaluronan, a nonsulfated glycosaminoglycan, is a hallmark feature of the tissue remodeling observed in thyroid-associated ophthalmopathy (TAO). Orbital fibroblasts have been shown to exhibit substantial up-regulation of hyaluronan synthesis when activated with proinflammatory cytokines such as interleukin-1beta (IL-1beta). Recently, three members of the hyaluronan synthase (HAS) gene family were cloned. Here we report that IL-1beta can dramatically and consistently induce in orbital fibroblasts the expression of HAS2 in the five orbital strains examined. HAS3 messenger ribonucleic acid (mRNA) was also detectable in all these strains by RT-PCR under both control and IL-1beta-treated conditions. In contrast, HAS1 mRNA was detected by Northern blot analysis in only one of the strains treated with IL-1beta, but in three of five strains examined by RT-PCR. These HAS inductions by the cytokine were time dependent and could be attenuated with dexamethasone and cycloheximide. They were accompanied by an increased incorporation of [3H]glucosamine into hyaluronan, and dexamethasone could attenuate induction of macromolecular synthesis as well. Our observations suggest that the cytokine-dependent induction of the HAS genes in orbital fibroblasts may be the molecular basis at least in part for the increased accumulation of hyaluronan, driven by immunocompetent cells, in orbital connective tissue and the extraocular muscles in TAO.
Collapse
Affiliation(s)
- L A Kaback
- Department of Medicine, Albany Medical College and Samuel S. Stratton Veterans Affairs Medical Center, New York 12208, USA
| | | |
Collapse
|
22
|
Smith TJ, Parikh SJ. HMC-1 mast cells activate human orbital fibroblasts in coculture: evidence for up-regulation of prostaglandin E2 and hyaluronan synthesis. Endocrinology 1999; 140:3518-25. [PMID: 10433207 DOI: 10.1210/endo.140.8.6881] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The purpose of this study was to determine the effects of mast cell coculture on human orbital fibroblasts. Thyroid-associated ophthalmopathy is characterized by infiltration of lymphocytes and mast cells and connective tissue activation in the orbit, leading to a disordered accumulation of hyaluronan and intense inflammation. Here, we report that HMC-1, an established human mast cell line, can activate human orbital fibroblasts to produce increased levels of prostaglandin E2 (PGE2) and hyaluronan when cocultured. HMC-1 cells up-regulate, in these fibroblasts, the expression of PG endoperoxide H synthase-2 (EC 1.14.99.1, PGHS-2), the inflammatory cyclooxygenase. This induction, at a pretranslational level, underlies the increase in PGE2 synthesis. The up-regulation can be attenuated with dexamethasone (10 nM), and the increase in PGE2 production can be inhibited by SC 58125, a specific PGHS-2 inhibitor. Moreover, anti-interleukin-4 receptor antibodies can block prostanoid production in the fibroblasts elicited by HMC-1 cells, suggesting that this cytokine might represent a molecular conduit for mast cell/fibroblast cross-talk. HMC-1 cells also increased hyaluronan synthesis, as was evidenced by a 2-fold increase in [3H]glucosamine incorporation into the macromolecule. To our knowledge, these findings are the first demonstrating the ability of mast cells to activate orbital fibroblasts, and the findings suggest a potential role for these cell-cell interactions in the pathogenesis of thyroid-associated ophthalmopathy.
Collapse
Affiliation(s)
- T J Smith
- Department of Medicine, Albany Medical College and Samuel S. Stratton Veterans Affairs Medical Center, New York 12208, USA
| | | |
Collapse
|
23
|
Smith TJ, Jennings TA, Sciaky D, Cao HJ. Prostaglandin-endoperoxide H synthase-2 expression in human thyroid epithelium. Evidence for constitutive expression in vivo and in cultured KAT-50 cells. J Biol Chem 1999; 274:15622-32. [PMID: 10336459 DOI: 10.1074/jbc.274.22.15622] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Prostaglandin-endoperoxide H synthase (PGHS) (EC 1.14.99.1) expression was examined in human thyroid tissue and in KAT-50, a well differentiated human thyroid epithelial cell line. PGHS-1 is found constitutively expressed in most healthy tissues, whereas PGHS-2 is highly inducible and currently thought to be expressed, with few exceptions, only in diseased tissues. Surprisingly, PGHS-2 mRNA and protein were easily detected in normal thyroid tissue. KAT-50 cells express high levels of constitutive PGHS-2 mRNA and protein under basal culture conditions. Compounds usually associated with PGHS-2 induction, including interleukin-1beta (IL-1beta), phorbol 12-myristate 13-acetate, and serum transiently down-regulated PGHS-2 expression. Human PGHS-2 promoter constructs (-1840/+123 and -831/+123) fused to a luciferase reporter and transfected into untreated KAT-50 cells exhibited substantial activity. NS-398, a highly selective inhibitor of PGHS-2 could inhibit substantial basal prostaglandin E2 production. Exogenous IL-1 receptor antagonist or IL-1alpha neutralizing antibodies could attenuate constitutive PGHS-2 expression in KAT-50 cells, suggesting that endogenous IL-1alpha synthesis was driving PGHS-2 expression. Our findings suggest that normal thyroid epithelium expresses high constitutive levels of PGHS-2 in situ and in vitro and this enzyme is active in the generation of prostaglandin E2. Thus, unprovoked PGHS-2 expression might be considerably more widespread in healthy tissues than is currently believed.
Collapse
Affiliation(s)
- T J Smith
- Division of Molecular and Cellular Medicine, Department of Medicine, Albany Medical College and the Samuel S. Stratton Veterans Affairs Medical Center, Albany, New York 12208, USA
| | | | | | | |
Collapse
|
24
|
Cao HJ, Wang HS, Zhang Y, Lin HY, Phipps RP, Smith TJ. Activation of human orbital fibroblasts through CD40 engagement results in a dramatic induction of hyaluronan synthesis and prostaglandin endoperoxide H synthase-2 expression. Insights into potential pathogenic mechanisms of thyroid-associated ophthalmopathy. J Biol Chem 1998; 273:29615-25. [PMID: 9792671 DOI: 10.1074/jbc.273.45.29615] [Citation(s) in RCA: 131] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Human orbital fibroblasts play a putative role in the pathogenesis of thyroid-associated ophthalmopathy (TAO). We hypothesize that the hyaluronan accumulation and inflammation in TAO derive from enhanced biosynthetic activities of orbital fibroblasts. CD40, a member of the tumor necrosis factor-alpha receptor superfamily, is a critical signaling molecule expressed by B lymphocytes. Engagement of CD40 with CD154 or CD40 ligand results in the activation of target genes. Orbital fibroblasts also display CD40. Here we report that CD40 engagement leads to substantial increases in hyaluronan synthesis in orbital fibroblasts. The increase is approximately 5-fold above control values, is comparable to the induction elicited by IL-1beta and could be attenuated with dexamethasone but not by SC 58125, a prostaglandin endoperoxide H synthase-2 (PGHS-2)-selective inhibitor. PGHS-2 is also induced by CD40 engagement in a time-dependent manner, and this is mediated through increases in levels of steady-state mRNA. The induction of PGHS-2 leads to a dramatically enhanced prostaglandin E2 production that can be blocked by SC 58125 and dexamethasone. CD40 ligand up-regulates the synthesis of IL-1alpha, and blocking this cytokine with exogenous IL-1 receptor antagonist (IL-1ra) or with IL-1alpha neutralizing antibodies partially attenuates the induction of PGHS-2. In contrast, CD40 ligand up-regulation of hyaluronan synthesis is unaffected by IL-1ra. CD40 cross-linking enhances mitogen-activated protein kinase activation, and interrupting this pathway attenuates the PGHS-2 induction. Thus the CD40/CD40 ligand bridge represents a potentially important activational pathway for orbital fibroblasts that may underlie the cross-talk between these cells and leukocytes. These findings may be relevant to the pathogenesis of TAO and provide insights into previously unrecognized, potential therapeutic targets.
Collapse
Affiliation(s)
- H J Cao
- Division of Molecular and Cellular Medicine, Department of Medicine, Albany Medical College and the Samuel S. Stratton Veterans Affairs Medical Center, Albany, New York 12208, USA
| | | | | | | | | | | |
Collapse
|